[en] Adding book on Open Source section

free-programming-books.md

@@ -416,6 +416,7 @@
 * [Free Software, Free Society](http://shop.fsf.org/product/free-software-free-society-2/)
 * [Free as in Freedom](http://static.fsf.org/nosvn/faif-2.0.pdf) (PDF)
 * [Getting started with Open source development](http://public.dhe.ibm.com/software/dw/db2/express-c/wiki/Getting_started_with_open_source_development_p2.pdf) (PDF)
+* [How to get started with open source](opensource.com/resources/how-get-started-open-source) (ePub & ODT)
 * [Innovation Happens Elsewhere](http://dreamsongs.com/IHE/IHE.html)
 * [Open Advice: FOSS: What We Wish We Had Known When We Started](http://open-advice.org/)
 * [Producing Open Source Software](http://producingoss.com/)